The invention relates to a method of manufacturing an electromagnetic relay comprising a yoke made of a ferromagnetic material and having a wall, and a coil core made of a ferromagnetic material and having a neck portion fixedly engaged in the yoke wall, which method includes displacing the coil core axially by deforming the yoke material until a predetermined dimension necessary for compensation of tolerances, is reached.
For the foregoing relays, it is important that magnetic resistance of the magnetic circuit is as small as possible. However, the foregoing relays, especially small ones, have a resistance which is often prohibitively high because area of connection or joint between the yoke and the coil core is rather short and, in addition, during operation of the relay, it is subjected to elevated temperature and cycle loads. It is also important that the pole surface of the coil core and the abutment for the relay armature are properly positioned relative to each other to thereby reduce the resistance. To this end, in a known relay, the core is pressed into the yoke wall until a desirable dimension is achieved. The drawback of this approach consists in that for insertion of the core into the yoke wall, a relatively large displacement force is needed for the core to displace the adjacent yoke wall material in the connection region. A further drawback consists in that the coil core need be made from a hard non-deformable material so that the core would not distort. Therefore, the known relay is relatively expensive.